Blood Pressure: Orthostatic (Ambulatory) - CE/NCPD

The content in Clinical Skills is evidence based and intended to be a guide to clinical practice. Always follow your organization’s practice.

ALERT

Do not check orthostatic vital signs in patients with supine hypotension, shock, or severe alteration in mental status or in those who may have spinal, pelvic, or lower extremity injuries.^{undefined#ref3">3}

Medications that block a patient’s normal vasomotor and chronotropic response will interfere with fluid volume evaluation; however, to evaluate a patient’s reaction to a medication, obtaining orthostatic vital signs can be helpful.

Anticipate that the patient may experience dizziness and that an assistant may be necessary to help move the patient from a lying to a standing position. Do not leave the patient alone during this procedure.

OVERVIEW

Orthostatic vital signs are performed with the patient in different positions. The measurement of orthostatic vital signs is sometimes referred to as postural vital signs or the tilt test. This measurement is used for noninvasive evaluation of fluid loss from conditions such as vomiting, diarrhea, diaphoresis, bleeding, abdominal pain, and blunt abdominal or chest trauma. A patient presenting with blood loss, diarrhea, or vomiting should be evaluated for orthostatic hypotension due to possible hypovolemia.⁵ Other indications for obtaining orthostatic vital signs include unexplained syncope, weakness or dizziness, and falls.⁵ A set of orthostatic vital signs can also help identify an isolated low blood pressure measurement.⁵ Orthostatic hypotension is impacted by increasing age, diagnosis of hypertension, and polypharmacy, including use of multiple antihypertensive medications.⁵

The value of orthostatic vital signs is disputed because there is no universal method on how to perform them or what blood pressure and heart rate changes constitute “positive orthostatics.” Orthostatic vital sign measurements are more accurate in suggesting hypovolemia than supine vital sign measurements alone.⁵ Therefore, the vital signs should be interpreted in the context of the patient’s other symptoms, such as dizziness, lightheadedness, fatigue, visual dimming, and shoulder pain.⁵ These symptoms can be aggravated by hot environments and in patients who tend to stand still without frequently changing position. Signs and symptoms of orthostatic changes are typically not present when the patient is supine but mostly materialize when moving into the standing position and can be quickly resolved by sitting or lying down.⁵

Another complicating factor in interpreting orthostatic vital signs is the development of paradoxical bradycardia associated with blood loss, trauma, or surgery. Bradycardia due to blood loss, trauma, or surgery has generally been considered a preterminal finding of irreversible shock, and bradycardia has been documented in hypovolemic, conscious trauma patients as well. It has been reported that when orthostatic syncope occurs, it is accompanied by hypotension and often bradycardia.³

SUPPLIES

See Supplies tab at the top of the page.

EDUCATION

• Give developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, preferred learning style, and overall neurologic and psychosocial state.
• Teach the patient the signs and symptoms of orthostatic hypotension (e.g., dizziness, lightheadedness, fatigue) and provide instructions on when to seek additional care.
• Encourage the patient to report feelings of dizziness or instability when changing positions during testing. If the patient feels dizzy or unstable, the test should be terminated, and the patient assisted to lie down before falling.
• Teach older adult patients and patients with postural symptoms about the importance of sitting for several minutes before getting out of bed and standing up slowly after sitting for an extended time.
• Encourage questions and answer them as they arise.

PROCEDURE

1. Clean hands and don appropriate personal protective equipment (PPE) based on the risk of exposure to bodily fluids or infection precautions.
2. Explain the procedure and be sure that the patient agrees to treatment.
3. Be sure that evaluation findings are communicated to the clinical team leader per the organization’s practice.
4. Determine the patient’s medication history.

   Rationale: Some commonly prescribed medications can affect the heart rate.¹ Drugs such as alpha blockers, beta blockers, tricyclic antidepressants, and antipsychotics have been associated with an increased finding of orthostatic hypotension.¹ Further, angiotensin-converting enzyme (ACE) inhibitors and calcium channel blockers can cause autonomic nervous system insufficiency.²

5. Be sure that the patient is lying in a flat, supine position for a minimum of 2 minutes^2,3,5 before taking the initial blood pressure and heart rate measurements.

   Rationale: The patient should be in a flat, supine position for the blood pressure to even out to a baseline supine pressure.

   Prevent unreliable results by avoiding invasive or painful procedures during the measurement of orthostatic vital signs.

6. Measure the patient’s blood pressure and heart rate after the patient has been in the supine position for the necessary amount of time (e.g., 2 to 10 minutes).^2,3,5 Use the appropriate-size blood pressure cuff. The correct cuff size is determined by arm circumference (Table 1).⁴ The length of the bladder on the cuff should encircle at least 80% of the circumference of the upper arm.²

   Do not use a cuff that is too small because it can result in falsely high readings. Do not use a cuff that is too large because it can result in falsely low readings.²

7. Assist the patient to a standing position.
   1. Assist the patient, as needed, with moving from a supine to a standing position.

      Rationale: Since hemodynamic changes are less pronounced when standing up from the sitting position versus standing up from the supine position, orthostatic vital sign measurements may be less sensitive in detecting orthostatic hypotension.³

      When moving the patient from supine to standing, enlist assistance from another health care team member to ensure patient safety.

   2. If the patient is unable to stand for a blood pressure measurement, help the patient to a sitting position.

      If the patient becomes extremely dizzy or experiences syncope, do not take measurements and have the patient lie down.³

8. Measure the patient’s blood pressure and heart rate, and check for symptoms upon standing or sitting.
   1. Take the measurements in the same arm as the initial reading.
   2. Be sure that the patient’s arm, relative to the patient’s trunk, is consistent with the arm’s position when the patient was supine.⁵
   3. Take the measurements again after 1 to 3 minutes^1,2,3,4,5 of standing or sitting.

      Rationale: Blood pressure and heart rate should be measured again after 1 to 3 minutes to confirm the persistent character of the blood pressure change.^1,2,3,4,5

   4. Ask the patient about symptoms of weakness, dizziness, or visual dimming associated with a change of position. Observe for pallor or diaphoresis.
9. Compare the blood pressure and heart rate results. When measuring orthostatic vital signs, one or more of these findings may indicate positive orthostasis (tilt test) in adults:^2,3,5
   1. Decrease in systolic blood pressure of 20 mm Hg or more
   2. Decrease in diastolic blood pressure of 10 mm Hg or more
   3. Increase in heart rate of 20 beats per minute or more
   4. Symptoms of cerebral hypoperfusion (e.g., dizziness, syncope)
10. Assist the patient as needed with returning to a supine or sitting position.
11. Monitor for the resolution of symptoms such as dizziness, visual changes, or hypotension if any occurred during the measurement of orthostatic vital signs.

EXPECTED OUTCOMES

• Accurate and safe measurement of heart rate and blood pressure with position changes

UNEXPECTED OUTCOMES

• Weakness, dizziness, syncope, and falls, which may be indicative of volume depletion
• Paradoxical bradycardia, which may be observed in hypovolemic patients who have rapid and massive bleeding and may be interpreted as orthostasis³

DOCUMENTATION

• Vital signs measurements, including position in which measurements were taken (e.g., with patient lying down, sitting, or standing), right or left arm, as well as patient reports of dizziness or visual changes
• Unexpected outcomes and related interventions
• Education
• Evaluation findings communicated to the clinical team leader per the organization’s practice

PEDIATRIC CONSIDERATIONS

• Postural near-syncope or an increase in heart rate of 25 beats per minute or more may be a predictor of dehydration in pediatric patients.³
• Assessment of dehydration in pediatric patients should be based on capillary refill and clinical assessment, as well as a comparison of the patient’s weight before and after the illness.
• Asking the family about the number of wet diapers changed per day helps to determine how often the patient is urinating in comparison to normal.

OLDER ADULT CONSIDERATIONS

• Patients with nondemand pacemakers or those taking beta blocker medications may not have significant changes in heart rate.
• Medications that antagonize the normal autonomic compensatory mechanisms in older adult patients can also produce orthostatic changes.³
• Older adult patients should be educated on the importance of sitting for several minutes before getting out of bed and standing up slowly after sitting for an extended time. Older adults have a higher incidence of orthostatic hypotension leading to syncope and fall-related injuries because of decreased vasomotor tone, limited chronotropic response, and other factors.³
• Older adults are at increased risk for falls in the presence of dehydration.

REFERENCES

1. Bhanu, C. and others. (2021). Drug-induced orthostatic hypotension: A systematic review and meta-analysis of randomised controlled trials. PLOS Medicine, 18(11), e1003821. Retrieved September 23, 2024, from https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003821
2. Lough, M.E. (2022). Chapter 12: Cardiovascular clinical assessment. In L.D. Urden, K.M. Stacy, M.E. Lough (Eds.), Critical care nursing: Diagnosis and management (9th ed., pp. 190-205). St. Louis: Elsevier.
3. McGrath, J.L., Bachmann, D.J. (2019). Chapter 1: Vital signs measurement. In J.R. Roberts and others (Eds.), Roberts and Hedges’ clinical procedures in emergency medicine and acute care (7th ed., pp. 1-22). Philadelphia: Elsevier.
4. Muntner, P. and others. (2019). Measurement of blood pressure in humans: A scientific statement from the American Heart Association. Hypertension, 73(5), e35-e66. doi:10.1161/HYP.0000000000000087
5. Witting, M.D. (2022). When and how to use orthostatic vital signs. Journal of Emergency Medicine, 63(3), 460-466. doi:10.1016/j.jemermed.2022.09.007

Clinical Review: Margaret E. Williams, PhD, RN, CRRN, FNP, DDP, FABDA, FARN

Published: November 2024